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1Division of Fruit and Vegetable Crops and Diseases, Bureau of Plant Industry, the U. S. Department of Agriculture, Raleigh, North Carolina
2The North Carolina Agricultural Experiment Station, Raleigh, North Carolina
1
Contribution from the Department of Agronomy, N. C. Agricultural Experiment Station and Div. of Fruit and Vegetable Crops and Diseases, Bureau of Plant Industry, U. S. Dept. of Agriculture. Published with the approval of the Director as Paper no. 150 of the Journal Series.